Saturday, June 27, 2015

Today the PACC results were published in the Dutch ham magazine Elektron. It turns out that we (YNOMY dx group) managed to secure second place in the multi operator single TX category only a few contacts away from the first place.As this was our second serious attempt in this contest (or for that matter any contest) I am really pleased with the results.The fact that we work from a temporary location where we build up our complete station from the ground with simple means just for the contest weekend makes this result even more pleasing.We have set ourselves a real challenge for next year...

Saturday, April 11, 2015

Within the YNOMY DX Group an idea was born at the beginning of this year to place special attention on this year's WW2 liberation celebrations as we have been living in peace here now for 70 years.

70 years ago the allied forces liberated The Netherlands from Nazi rule, ending the second world war five years after it started. The southern part of The Netherlands was liberated in the autumn of 1944, while the northern part was only liberated in the spring of 1945.

On May 4, 1945 the German forces formally capitulated to the British Field Marshall Montgomery. The capitulation was effective the next day.

We therefore celebrate the end of WW2 for the whole of the country on May 5 every year ("bevrijdingsdag").

We were thinking of activating a range of special calls during the month of May with a group of operators. The range P*45FREE (PA-PH) was chosen after some debate. We also planned a group activity in the middle of the month with a special group call PA45FREEDOM.

We asked around and were able to organise a team of 9 operators that were supportive of the idea and willing to play a role in it by applying for and activating one of the special calls. The team consists of PA1WBU, PA3BAS, PA3FYG, PB7Z, PD7YY, PE1BVQ, PE4BAS, PG8M and myself.

So we are moving from an idea to a whole range of special event stations that will be active during the month of May 2015.

In the mean time we have designed a special QSL card and are in the process of designing an award. This electronic award can be obtained free of charge when an OM or SWL has collected 45 points. Each P*45FREE counts for 9 points and the PA45FREEDOM call counts for 18 points towards the award.

Wednesday, February 25, 2015

For me data makes (far more) sense once it is visualised. So I spent some time with our PACC log data to transform it into pictures.The easiest way of course is by totaling numbers of QSO per time slot, band and / or mode. You can display this in all sorts of nice graphs.There is another way to do it, and it is one I really like: showing the actual QSOs mapped on the planet earth. This took quite some time as the N1MM logger we used during the contest does not log / retrieve the location of the station worked. Using HRD LogBook as intermediate I retrieved this data from QRZ.com.Now with some minimal programming I was able to show the contacts plotted on the globe per time slot, per band and per mode. I made several maps with different segmentations of the data.I liked this animation I made best - it shows our progress over time (with 1 hour increments). The colors of the data points represent the bands and the shape represents the mode used.

Sunday, February 22, 2015

Cross-posted from the YNOMY blog siteYNOMY is a team of 3 active OMs from around Arnhem - PD7YY, PG8M & PH0NO

Pre-contest preparation

We prepared ourselves a bit better than last year (which already was a lot better than the first year). We got ourselves a nice temporary special call PE55E and we constructed and tested a number of different wire antennas well before the contest (last year M was still working on the 160m antenna a few hours into the contest).

Pre-contest modeling of our wire antennas

M had arranged a proper location at a camping ground near to where he lives and - importantly for this contest - in our province of Gelderland. The place definitely was an upgrade of the cold and windy hut we were in last year. It even featured WiFi so we had online cluster info in N1MM.

Our shack during PACC 2015

M started the installation of the antenna park together with his station manager on Friday. They installed the three main poles - 12m, 18m and 12m high - that were holding the wire dipoles for 160m (supported by all three poles), 80m (inverted v from the center pole) and 40m (inverted v from the nearest pole).

Low band wire antennas

We tested this setup before (more info in this post). Modelling showed this setup results in more gain on 160m and less gain on 40m than last year. As we would be running 3 to 4 times the power of last year on the low bands we weren't too focused on getting the maximum gain though.

Final preparations

Saturday morning NO and YY arrived to complete the contest station, adding an end fed for 20m, a hex beam for 20-15-10m and a yagi for 10m. As NO had to leave Sunday morning before the end of the contest - taking the hex and the yagi - we set up an extra 5/8 vertical for 15m we built and tested just 2 weeks before the contest.

Our beams: portable hexbeam and home brew 3 element yagi

When we finished setting up the station we had 7 antennas at our disposal - quite an impressive set-up for a temporary station. We were running 300-400 watts PEP into them via an icom 756P3 hooked up to a pc running N1MM.

Contest operation

We manned the station for 24h by sleeping in shifts. The camping provided us with two extra sleeping places conveniently located outside the noisy shack.M was our CW operator while YY and NO took care of the phone contacts.

M on CW logging in N1MM with YY following the proceedings closely

As the weather was much friendlier than last year we had no calamities (as blogged about in this post). All went rather smoothly. Conditions on the high bands seemed a bit better than we remembered from last year. We will have to compare our logs to see how this worked out.

A better preparation allowed us to operate with minimal switching times between operators. We used our experiences from last year to choose the right band and mode at the right time and we had more power at our disposal on the low bands (300-400w as opposed to 100w last year).

This has resulted in far more contacts and more multipliers than last year. We logged approx. 800 contacts last year during our first real try in this contest and came in 6th place. This year we set our goal at 1000 QSOs and surpassed that by a considerable margin.

We will add more information about our results once we have taken the time to run our log through the PACC log robot and compare our results in more detail with the results of last year (numbers, multipliers, dx per band).

Thursday, January 1, 2015

A power hungry mobile amplifier For my portable operations I sometimes use an RM transistor amplifier. It is a very simple amp and probably not the cleanest one around - although I have had no complaints as long as don't use compression on the lower bands. Recently I bought a dummy load and was able to measure the output. It delivers 300-400 watts from 10m-160m depending on the band (less on the higher bands).I power the amplifier with a separate car battery - the wiring in my car does not support the high currents and I do not want to run the risk of draining the battery I need to get moving again.This works well even when I now and then want to use the amplifier at home (I usually refrain from using more than 100 watts as my neighbors have complained of RFI in the past). However with our PACC contest coming up I was looking for a power source that could last longer than the car battery does. We used the amplifier last year during the first hours of the contest and we think it could help us score better this year if we have it available for 24 hours.A proper power supplierI have not measured the peak current yet but I would expect it to be around 50A. I could of course buy a decent switching power supply of say 60A to have a bit of head room. However they don´t come cheap.

ATX PSU in use for LiPo charger

In the past I converted an ATX power supply of 400W from a desktop PC to a bench power supply (3.3V, 5V, 12V). It delivers 15A max @12V which is nice for recharching my LiPo and LifePo batteries. Thinking along these lines I stumbled on server power supplies being used as 12V power sources. The best information how to use these I found in the realm of remotely controlled helicopters and cars. That is quite another hobby but one I met before when I was looking for the best portable batteries in power/weight. They seem to have similar challenges as ham radio operators.

The DELL server PSU capable of delivering a whopping 175A

One power supply that attracted my attention was from a DELL server that could deliver 175A @12V. That is what I call head room :)I found it for sale as a refurbished part in the Netherlands for a good price so I ordered it earlier this week and it arrived just before the year ended.

Using the information online I am now preparing it to power up. For this you need to connect the right pins so the PSU thinks it is correctly installed in the DELL server. According to the information online it is even possible to increase the voltage supplied using a potentiometer between certain pins. Sounds all very nice to me..

I still need a few parts to complete the job and when done I will add the details to my Projects page.